Remove special-case build tags (#98)
The purego tag should cover all environments (e.g., gopherjs and appengine)
that do not support unsafe.
diff --git a/cmp/unsafe_panic.go b/cmp/unsafe_panic.go
index d1518eb..8193f08 100644
--- a/cmp/unsafe_panic.go
+++ b/cmp/unsafe_panic.go
@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
-// +build purego appengine js
+// +build purego
package cmp
diff --git a/cmp/unsafe_reflect.go b/cmp/unsafe_reflect.go
index 579b655..926fd47 100644
--- a/cmp/unsafe_reflect.go
+++ b/cmp/unsafe_reflect.go
@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
-// +build !purego,!appengine,!js
+// +build !purego
package cmp
